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Lennart E Nilsson

Publications and source records attributed to Lennart E Nilsson.

10 recordsLinked to original sources
PubMed2026

Antibiotic-impregnated bone graft to prevent infection after total hip arthroplasty (ABOGRAFT): protocol for a randomised, double-blind, placebo-controlled trial.

INTRODUCTION: Studies have shown promising results using bone graft as a carrier for local administration of antibiotics to reduce the risk of prosthetic joint infection (PJI). The objective of this clinical trial is to determine if tobramycin and vancomycin-impregnated bone graft is safe and effective in reducing the rate of PJI after total hip arthroplasty (THA). METHODS AND ANALYSIS: This study is an international, randomised, double-blinded, placebo-controlled clinical drug trial. Patients scheduled for THA (n=1100) requiring bone grafting (excluding revisions due to an ongoing infection) are randomised in a 1:1 ratio to prophylactic treatment with tobramycin and vancomycin or placebo-impregnated bone graft.The primary outcome is the time to reoperation due to infection or diagnosis of PJI, expressed as a relative risk difference between the two groups. A risk reduction of at least 50% is considered clinically relevant. Secondary outcomes are time to and reason for reoperation and implant revision, type of micro-organism and antibiotic susceptibility pattern within 2 and 5 years after surgery. Safety outcomes are the number of adverse events and revision rate due to aseptic loosening. The primary analysis will be performed using proportional hazard models. ETHICS AND DISSEMINATION: The study has been approved under the Clinical Trial Regulation No 536/2014 (EU CT; 2024-510921-25-00). Results will be published in open-access peer-reviewed journals and disseminated to patient organisations and the media, and de-identified individual participant data will be curated and shared on reasonable request in accordance with the Findability, Accessibility, Interoperability and Reuse principles, subject to the laws and regulations governing data protection in each participating country. TRIAL REGISTRATION NUMBER: NCT05169229.

Humans↗
PubMed2006

Epidemiological MIC cut-off values for tigecycline calculated from Etest MIC values using normalized resistance interpretation.

OBJECTIVES: To apply the normalized resistance interpretation (NRI) method to Etest MIC results which have higher precision than conventional log2 dilution MIC tests due to the inclusion of intermediate values. If successful, NRI might provide an objective tool for the definition of epidemiological MIC cut-off values. METHODS: MICs of tigecycline and other antimicrobial agents were determined for 4771 clinical isolates comprising five Gram-positive and 13 Gram-negative species or species groups using the Etest. Histograms of MIC values were constructed for each species and NRI calculations were applied to them. An upper MIC limit of 2.5 SD above the theoretical mean of the normalized distribution was used for setting the epidemiological cut-off values. RESULTS: Calculated cut-off values for wild-type strains were between 0.11 and 0.96 mg/L for Gram-positive species, and between 0.44 and 8.3 mg/L for Gram-negative species, except for Pseudomonas aeruginosa, which had a cut-off value of 450 mg/L, consistent with earlier reports on the lack of activity of tigecycline against this species. CONCLUSIONS: NRI offers an objective method for the analysis of MICs produced using Etests and the determination of epidemiological MIC cut-off values.

Anti-Bacterial Agents↗
PubMed2005

Rectal colonization and frequency of enterococcal cross-transmission among prolonged-stay patients in two Swedish intensive care units.

The aims of this study were to gain insight into the dynamics of the rectal flora during prolonged ICU stay, with a particular focus on colonization and cross-transmission with resistant pathogens, and to evaluate methods for the rapid isolation of relevant bacteria from rectal swabs. Patients admitted to a general intensive care unit (GICU) or a cardiothoracic ICU (TICU) at the University Hospital of Linköping, Sweden, between 1 November 2001 and January 2002 with a length of stay > 5 d were included (n = 20). Chromogenic UTI agar medium was used for discrimination of different species, and appropriate antibiotics were added to detect resistance. Direct plating was compared to enrichment broth for a subset of specimens. The study showed an early alteration in rectal flora, with a dramatic decrease in Gram-negative rods in favour of Gram-positive bacteria. An ampicillin- and high-level gentamicin resistant clone of Enterococcus faecium was found in 6 of 10 patients in the GICU and 2 of 11 patients in the TICU. Enrichment broth did not enhance the detection of Gram-negative bacteria compared to direct plating on Chromogenic UTI medium, but enrichment broths were needed for optimal detection of resistant Gram-positive bacteria.

Aged↗
PubMed2004

High antibiotic susceptibility among bacterial pathogens in Swedish ICUs. Report from a nation-wide surveillance program using TA90 as a novel index of susceptibility.

Local infection control measures, antibiotic consumption and patient demographics from 1999-2000 together with bacteriological analyses were investigated in 29 ICUs participating in the ICU-STRAMA programme. The median antibiotic consumption per ICU was 1147 (range 605-2143) daily doses per 1000 occupied bed d (DDD1000). Antibiotics to which > 90% of isolates of an organism were susceptible were defined as treatment alternatives (TA90). The mean number of TA90 was low (1-2 per organism) for Enterococcus faecium (vancomycin:VAN), coagulase negative staphylococci (VAN), Pseudomonas aeruginosa (ceftazidime:CTZ, netilmicin: NET) and Stenotrophomonas maltophilia (CTZ, trimethoprim-sulfamethoxazole: TSU), but higher (3-7) for Acinetobacter spp. (imipenem:IMI, NET, TSU), Enterococcus faecalis (ampicillin:AMP, IMI, VAN), Serratia spp. (ciprofloxacin:CIP, IMI, NET), Enterobacter spp. (CIP, IMI, NET, TSU), E. coli (cefuroxime:CXM, cefotaxime/eftazidime:CTX/CTZ, CIP, IMI, NET, piperacillin-tazobactam:PTZ, TSU), Klebsiella spp. (CTX/CTZ CIP, IMI, NET, PTZ, TSU) and Staphylococcus aureus (clindamycin, fusidic acid, NET, oxacillin, rifampicin, VAN). Of S. aureus isolates 2% were MRSA. Facilities for alcohol hand disinfection at each bed were available in 96% of the ICUs. The numbers of TA90 available were apparently higher than in ICUs in southern Europe and the US, despite a relatively high antibiotic consumption. This may be due to a moderate ecological impact of the used agents and the infection control routines in Swedish ICUs.

Adult↗
PubMed2004

Genetic relatedness of Enterococcus faecalis isolates with high-level gentamicin resistance from patients with bacteraemia in the south east of Sweden 1994-2001.

High-level gentamicin resistant (HLGR) enterococci (Enterococcus faecalis and Enterococcus faecium) have become a substantial nosocomial problem in many countries. In this study, we investigated the prevalence of HLGR enterococci and their genetic relatedness in blood culture isolates from patients with bacteraemia admitted to the 3 hospitals in Ostergötland, a county in the south east of Sweden, during 1994-2001. 36 of 250 E. faecalis (14%,) and 4 of 106 E. faecium isolates (4%) were shown by PCR to carry the aac(6')-Ie-aph(2")-Ia aminoglycoside modifying gene and these isolates were also classified as HLGR enterococci by the gentamicin antibiotic disk diffusion method. A majority of HLGR E. faecalis isolates (83%) belonged to the same cluster of genetically related isolates, according to the pulsed-field gel electrophoresis (PFGE) patterns, whereas all 4 HLGR E. faecium isolates had unique PFGE patterns. In conclusion, our study showed that in contrast to studies from many other countries, the presence of HLGR enterococci was more common in E. faecalis than in E. faecium and appeared the first time in 1996 and 1999, respectively. Bacteraemia with HLGR enterococci in Ostergötland was mainly due to the spread of a cluster of related E. faecalis strains.

Anti-Bacterial Agents↗
PubMed2003

Genetic relatedness among Enterococcus faecalis with transposon-mediated high-level gentamicin resistance in Swedish intensive care units.

We studied 45 isolates of Enterococcus faecalis with high-level gentamicin resistance (HLGR), all but one concomitantly resistant to ciprofloxacin, and 25 ciprofloxacin-resistant isolates without HLGR for genetic relatedness using pulsed-field gel electrophoresis (PFGE). E. faecalis were isolated from patients admitted to intensive care units at eight hospitals in southern Sweden from December 1996 through December 1998. Genomic analysis by PFGE resulted in three clusters of genetically related isolates (designated clusters I, II and III) and 23 unique clones. Cluster I was found predominantly in the eastern and central parts of southern Sweden and clusters II and III in south-western Sweden. Among the 45 isolates with HLGR, 69% belonged to cluster I, 20% to cluster II, and 11% had unique PFGE patterns, which suggests that the majority of isolates with HLGR are closely related. Among the 25 ciprofloxacin-resistant isolates without HLGR, 68% had unique PFGE patterns, 12% belonged to cluster I and 20% to cluster III, which suggests the ciprofloxacin-resistant isolates are not related. All isolates with HLGR contained the aac(6')Ie-aph(2")Ia gene, which was carried on a Tn5281-like transposon in all isolates except one. We conclude that HLGR in E. faecalis was mainly due to dissemination of genetically related clones during the time studied, and that HLGR in these isolates was due to the presence of the aac(6')Ie-aph(2")Ia gene.

Cross Infection↗
PubMed2003

Profiling and identification of eubacteria in the stomach of Mongolian gerbils with and without Helicobacter pylori infection.

BACKGROUND: Mongolian gerbils are frequently used to study Helicobacter pylori-induced gastritis and its consequences. The presence of an indigenous bacterial flora with suppressive effect on H. pylori may cause difficulties with establishing this experimental model. AIM: The aim of the present study was to determine bacterial profiles in the stomach of Mongolian gerbils with and without (controls) H. pylori infection. METHODS: Gastric tissue from H. pylori ATCC 43504 and CCUG 17874 infected and control animals were subjected to microbial culturing and histology. In addition, gastric mucosal samples from H. pylori ATCC 43504 infected and control animals were analyzed for bacterial profiling by temporal temperature gradient gel electrophoresis (TTGE), cloning and pyrosequencing of 16S rDNA variable V3 region derived PCR amplicons. RESULTS: Oral administration of H. pylori ATCC 43504, but not CCUG 17874, induced colonization and gastric inflammation in the stomach of Mongolian gerbils. Temporal temperature gradient gel electrophoresis (TTGE) and partial 16S rDNA pyrosequencing revealed the presence of DNA representing a mixed bacterial flora in the stomach of both H. pylori ATCC 43504 infected and control animals. In both cases, lactobacilli appeared to be dominant. CONCLUSION: These findings suggest that indigenous bacteria, particularly lactobacilli, may have an impact on the colonization and growth of H. pylori strains in the stomach of Mongolian gerbils.

Animals↗
PubMed2002

Modified pulsed-field gel electrophoresis protocol for typing of enterococci.

Controlling the spread of vancomycin-resistant enterococci (VRE) is an important task in hospital epidemiology. Pulsed-field gel electrophoresis (PFGE) has become the golden standard for molecular epidemiological characterisation of enterococcal isolates. For separation of DNA fragments by PFGE, different electrophoresis conditions have been recommended, but none of these protocols allows a satisfactory separation of both small and large DNA fragments of enterococci simultaneously. In this study we have speeded up the preparation of chromosomal DNA and defined new electrophoresis conditions that enhance separation of small and large DNA fragments for subtyping of enterococci with a 24 h PFGE.

Bacterial Typing Techniques↗
PubMed2002

Pharmacodynamic effects of nitroimidazoles alone and in combination with clarithromycin on Helicobacter pylori.

Pharmacodynamic studies of Helicobacter pylori exposed to metronidazole and tinidazole alone and in combination with clarithromycin were performed by bioluminescence assay of intracellular ATP. The pharmacodynamic parameter control-related effective regrowth time (CERT) was used. CERT is defined as the time required for the resumption of logarithmic growth and a return of the level of growth to the preexposure inoculum in the test culture minus the corresponding time in the control culture. CERT measures the combined effects of the initial level of killing and postantibiotic effect. The incubation times and drug concentrations were chosen according to their half-lives and their clinically achievable concentrations. The study shows that the parameter CERT is useful for the testing of antibiotic combinations. The CERTs induced by clarithromycin, metronidazole, and tinidazole alone and in the combinations tested were concentration dependent, with no maximum response, indicating that the use of high doses may be preferable. The combinations with the highest concentrations induced synergistic effects and prevented regrowth. The use of tinidazole in combination with clarithromycin proved to give the longest CERTs, indicating that this is the most effective combination.

Clarithromycin↗